Synchronized centrifugal clutch



Patented Oct. 14, 1952 UNITEDQ-VSTATE f f ISYNCHRONIZED .CENTRIFUGA-L CLUTCH "Edwin E. Maureri Detroit, Mich., assignor to 1 v Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Original application February 19, 1945, Serial No. I 578,631. Divided and this application July 24,

'- 1948, SerialNo. 40,567

13 Claims. (Cl. 192-105) This invention relatesstolpower transmitting drives providing a pawl clutch of the centrifugal type engageable to dri-vingly connect a driving and a driven'member.: More particularly my invention has reference :to centrifugal pawl clutch mechanism providing means for controlling the pawl engagement, for example, whereby it may be made operablysresponsive to certain predetermined conditions-'0?operation of the drive structure with which the clutch mechanism is associatedl: .Thepresent, application is a division of myicopending applicationSerial No. 578,631 filed 'Eebruary 19, 1945, now Patent No. 2,448,539., 1 x Y My invention Will.:be--,i1lustrated as applied to a centrifugally actuated'pawl clutch mechanism for locking together against slip under certain conditions .of'vehicleyoperation' a :pair of fluid power transmitting: -e1ements,; which clutch mechanism includes a.-d rivingmember drivingly associated with. one. ofrsaid power transmitting elements, a driven: member ;drivinglyassociated with the other of the power transmitting ele: ments, a locking pawl 3- carried by joneof the members and operably: responsive to centrifugal force'upon; predetermined rotation of said one member for interconnecting said-clutch elements and means iforpreventing the operation of the clutch mechanismfor positively locking together. 'the ,fluid power transmitting "elements until the r-otative gspee f th-e clutchmemb ers have been first brought; o r-approximate synchro; nism. M :5 I

An object of the nyentiontherefore, is to provide an automatically operable clutch mechanism with means oper -ble-,in response to inner tioning of .the powe transmitting drive structure in which the clutch mechanism is incorporated forcontrolling engagement of the clutch mechanism.

Another object is to :provide a centrifugal type pawl clutch mechanism: foranaut-omotive vehicle drive structure withblocker means operable automatically under certain conditi'ons of vehicle functioningrfor ositively preventing engagement of the pawl v- A more particular fobject is the provision of control means aforesaid in the nature of a frictionally driven balk ring interposed between the pawls and pawl receiving: recesses and having circumferential'slots through which" the'centrifugal pawl may bep'r'ojected. into engagement to lock up the clutchni'ec'hanisin and which rin is constantly maintained. byi'resilient m'ea'ns' in frictional contact withijfoneof the driving 'or driven members.

Other objects 0am" ent from the followin ing wherein: "f

Fig. l is a sectional' viewinfelevationcf a'por- .1'n:vention-lwill be appar- 'c ription and the drawthereto by bolts 19.

tion of a transmission embodying the present invention; and V e v Fig. 2 is a sectional view taken along the line 2,-2 of Fig. 1; 7 r Referring to Figs. 1

and 2, it will be seen that there is illustrated a fluid power transmitting.

device such as a fluid coupling havin an irnpeller I0 provided with an annular ring ll by which it is carried on a hub 12 which is fastened toan engine crankshaft l3 by means of studs [4 and nuts IS. The impeller includes a housing portion l-B which encloses a runner I'I, the latter'being welded to a hub I8 or fastened v A forward seal and. a rearward seal 2| prevent leakage oi fluid which is circulated in the passages formed by the vanes 22, as is common in the art. The. runneri hub l8 has a tubular driven portion 23. by; which drive is imparted to the input memberof the vehicle transmission. This tubular portion, as shown, pilots a transmission shaft 24. The impellerv hub I2 also serves as the pawl drivemember of a centrifugal clutch, it having a rearward pawl carrying core portion 25 formed ;with a shoulder 26 and which is slotted to carry a pair of pawls 21. v The pawls are movable radially outwardly in response to centrifugal force act .ing upon the .pawls during rotation of the iin peller hub l2. The pawlsl'l are an element. of

the centrifugal; clutch and have cars 28 provid ed with recesses 29 for receiving a coil compression spring '30 of predetermined force value which tends to keep the pawls in retracted, that is, disengaged position; v

The pawlsare shaped as illustrated in Fig. 2, Each has an integral tail portion 3| which lies alongside a portion 32 of the head 33 of the pawl and acts as a drag ing connection between the pawl and the hub 12 as well as a, guide to keep the pawl-s in position. The pawl carrying core 25 is provided with rearwardlyproject ing annular segments 34, 35 which .serve as guideways for the head 33 and tail 3'! of the pawls and further provide a driving connection between the hub l2 and thepawls.

The pawls loosely embrace the core 25 and havejsufiicient clearance in the slotted guideways 36 such that they may move radially outwardly under the influence of centrifugalforce or be retracted by the springs30. This movement is limited in both directions by engage ment of the inner surface 31 of the pawls wi h thefshoulder -26 of the pawl core 25 or by abutment of the pawl ears- 2.8 with the adjacent previously indicated, providea slotted gnideway I 36 for the pawl head andtail portions.

The spr1ngs30 may be of i any desired strength openings 42.

to produce the operating characteristics desired, it' beingnnd'erst'ood that thesprings will keep the pawls in the illustrated retracted position until a predetermined speed of the drive hub 12 is reached whereupon centrifugal force will overcome the force of the springs 30 and the pawls will tendto move radially" outwardly as explained below.

The runner hub i8 carries a baffle 40 for reducing the efficiency of the coupling at idlin speed and for preventing surges and is formed with a forwardly projecting annular portion 41 constituting the driven member of the centrifugal clutch. The portion 4| is provided with circumferentially spaced notches or pawl receiving Two openings 42 re shown but more maybe required in some installations.

Theop'enings 42 are shown radially aligned with the'pawls 21 such that the pawls may if outwardly projected by centrifugal force engage the openings '42 to positively lock the impeller hub {I2 in 'drive' with'the runner hub 18. "The pawls 21 are formed with an outer cammed sur -i face '43 which is 'shapedsuch'that when the pawls'are urged outwardly by" centrifugal force if the annular portion '4! of the 'runner'hub'ltl rotatably lags'behind the impeller hub I Zfthe surface 43 will engage theedge 44 of the open-f ings 42 and cam'the pawls inwardly until the speeds of] the two members areag ain sub'Stan tially synchronized, whereupon the pawls will enter'theopenings 42.

In operation of thedevice so far described, let it be assumed that the parts arein thepb: sition-illustrated with the vehicleengine, hubs l2 and I8 and the 'shafts23 and 24 at' rest The engine may be started infthehormal manner and'theflvehicle may then be accelerated, ma-

of centrifugal force tend to move outwardly to engage the openings42 They will beprevented from engaging the openings,"however, so long as the rotative spe'edsof the pawls and the hub lila-re different as 'they'normally' will be because of the slipping between the impeller and runner of the couplings The driver c'an effect engagement of the pawls momentarilyreleasingthe engine throttle whereupon the impeller will drop in speed relative to the runner and the pawls will'engage at the instant of synchronism between'these'members;

Unless some means be provided for positively blocking or locking up the pawls under a synchronous conditions the pawls will ratchet past the pawl units or openings 42 to produce a noisy operation andwear and under certain conditions even breakage of the pawlsf 'Tol positively block 'movement of the pawls into' engagement under asynchronous conditions of operation I'have provided, as showiia balkin'g ort qekm ring in'uie' nature of a con: tinuous 'circumferential'band 45' having "circum ferenti'ally spaced openings 46 extending therethrough which, as shown 1h Fi 2,"areh1 ned with' the clutching ends 43 'of'head portions 33 ofthe' 'jpawls 21 and which, as shownja're of greater circumferential extent than the clutch ing-"ends' 43." This band 45; islpreferably carried in frictional engagement with the innerperiphery'of the annular portion 4| of the hub I8 or frictionally engaged therewith as hereinafter described. Projections in the form of pins 48 rigi lycarriedby the portions, 35 of the pawl carrying core" 251 are received in openings or clocking slots 49 in the ring 45. These slots 49 are of sufficient circumferential length to permit limited relative movement between the pins 48 and the ri'ng'45 to the extent permitted by the slots :49 from the neutral position illustrated in'lfig'; '2; It will be evident that when the pins 48 are at either end of the slots 49, the pawl receiving openings 46 of the rings 45 are misaligned radially speaking, relative to the pawls 21fsucli that portions of the ring 45 overlap the ends 43 of the pawls and hence block movement of the pawls past the ring 45.

Thus, for example, as the band 45 is moved in a cl ockwise orcounterclockwise direction by frictional' drag of the annular portion 4! of the runner hub l8the pins'limit the relative movement of the band '45 and' the pawl carrying cage or'core'25. The frictional engagement referredlto" is constantly'present by reason of a tapered'rearward' face50 on the ring 45 which is *biasedinto"constant friction'aI engagement with a complementarytapered surface 5| on the "interior surface er. the annular portion M of the'hub' le y a'fin'gerspring 52 which bears against'the opposite"end of the ring 45 and a shoulder 53 of'the pawl" carrying core 25. Once the pins limit the relative movement of the band and pawljcarryingcore the annular portion of tliehubWBfsIipS thereafter relative to the s I similarly if the pawl carrying core is moved in eitherdirection r'lative to the runner l1 and the annular portionill, the pins 48 will move to either end tiftheslots 49 of the ring and thereafter the "ring will'continue to move with the pawl carrying core In either described case, misalignment of 'the'openings 46 of the ring'45 with the pawls 2'! results, thus preventingthe latter froinfente'ring'the openings 42 of the annular portion]! of the runner hub l8. Under drive "conditions, "after the vehicle has been accelerated to a predetermined speed, if the accelerator is" momentarily released, the impellerwill be"deceleratd and become synchronize'd'with the "runner which will then try to overrun the impeller. At this moment the fric tionaldrag between thering 45 and the anof the ring relative 't'oth'e pins 48 to permit the openings 42 of the ring to become aligned with the pawls 2] such that the latter may pass through these openin'g's14'6. This outward movement of the pawls 21 is facilitated by the adequate .lengthpf the" slots 46 and the entry of the high portion of the pawl into the slots. 'Thereaftenas soon'as a, slot 42 of the clutch annularfportionofjthe hub I8 is aligned with a pawl 21, the latter "willbe projected into engage ne t with the openings, 42 by the action of, centrifu e, thereby establishing a posthejimpeller and runner. as co d tignsfof vehicle operation as rotating forwardly at greater I impeller, the ring 45 will be driven by the f -"rial"engagement with the Y h b membe nt l' lie 05 m i between Sl 8'f'1 1 ken u whereupon further forw 'd' rotationofthe ring 45 with the hub 18 will ceaseand the ring 45 will roa a lr a b hin thevrunnerthe e e rator is thereupon depressed to speed up the rotative v locityjof the. impeller to effect synchronism with the runner, the pins will first nula'r portionlll 'will eifect'relative movement amp-s into engagement with the pawl openings. of

the runner hub portion 4l' thereby forming a positive lockup between the impeller andrunner. Should for some reason thepawls 21 not pass through the openings 46, thepins. 48 will move to the other ends of the slots 49 again blocking the pawls from engagement which may there-, after be engaged upon momentary release of the accelerator in the manner described above.

The impeller and runner following engagement of the pawls will remain locked for joint operation without slippage so long as the impellertends to overrun the runner as would be the case during normal driving of the vehicle by the engine or as long as the runner tends to overrun the impeller as under coast conditions described above. When the pawl carrying core has its, speed reduced below the engaging speed of the pawls as when the vehicle is brought to a stop, the'pawls will under urging by the springs 35 become disengaged from the pawljreceiving openings. 42. Should thereafter the relative speeds of the pawl carrying core 25 and the hub 18 become asynchronous the ring 45 will again be moved into blocking relationship with respect to the pawls 21.

From the foregoing description of my invention it will be understood tha-tjI have provided a simgagement of said pawl during asynchronous rotation of said members, said ring having an opening therein for permittingpass'age throughlofsaid pawlfor efiecting engagement thereof and h'av-' ing circumferential portions at the opposite ends ofsaid opening for providing said blocking engagement. V

3. A-"power transmitting clutch mechanism 1 comprising 'a rotatable driving member, a coaxial driven member, a centrifugally responsive pawl carriedby one of said members and interenga'geable with the other of said members at a predetermined rotative speed of said one member and substantially synchronous rotation-of said members, a ring in alignment with said pawl transversely of the member'axis for blocking engagement of. said pawl during asynchronous rotation of said members, said ring having anjopening therein for. permitting passage through-of said pawl for efiecting'engagement thereof and having portions at each end thereof for providing said blocking engagement, and spring means for 'biasing said ring into frictional drive connection with said other member.

.4. A power; transmitting clutch mechanism comprising a rotatable driving member, a coaxial driven member, a centrifugally responsive pawl ple and desirable control construction-for retain- I ing the pawls of a centrifugal clutch in a predetermined position until certain vehicle'operating conditions have been reached in responseto which such control means may release the pawls for engagement. 1

While the particular structures herein described are well adapted for carrying out the objects of my invention it will be understood that various modifications, changes, and substitutions maybe 7 made without departing from thespirit thereof, for example, various changes in the size, shape,

, and arrangement of the parts may be made by mined rotative speed of said one member and substantially synchronous rotation of said members, a ring having a cylindrical outer wall in alignment with said pawl transversely of the member axis, said wall having a slot through which the pawl may be projected and having a portion adjacent the opposite circumferentialends of said slot for blocking engagement of said pawl duringasynchronous rotation of said members and spring means for biasing said ring into frictional drive connection with said other member.

2. A power transmitting clutch mechanism comprising a rotatable driving member, a coaxial driven member, a centrifugally responsive pawl carried by one of said members and inter-engageable with the other of said members at a predetermined rotative speed oflsaid one member and substantially synchronous rotation of said members, and a ring in alignment with said pawl transversely of the member axis for blocking encarried by onezof said members, an annular por positively connect said members in drive, and

aring in alignment with said pawl transversely of the member-axis" and having spaced portions for interposition between the engaging end of said pawl and said annular portion to block engagement of said pawl with said opening during asynchronous rotation of said members, said ring having an end portion thereof in frictional drive connection with said other member and having a recess therein between said spaced portions for permitting passage therethrough of the pawl when effecting engagement thereof with said opening. j

' 5. A power transmitting clutch mechanism comprising a rotatabledriving member, a rotatable driven memberfa centrifugally responsive pawl carried by one of said members, an annular portion on said other member having an opening therein for receiving said pawl at predetermined speed of said one member'and substantially synchronousrotation of said members whereby to positively connect said members in drive, and means for blocking engagement of said pawl in said opening during asynchronous rotation of said members comprising a ring internally of said annular portion, said ring having a. recess therein in the plane of said pawl receiving opening permitting passage therethrough of said pawl when effecting engagement with said opening, portions at the ends of said recess for blocking pawlengagement and an end face for frictional engagement' with a face on said other member to establish a frictionaldrive between said ring and other sive pawl carried by one of said members, an

annular portion on said other member having an opening therein for receiving said pawl at predetermined speed of said one member and ing portions engageable with a complementary tapered surface on said other member, anda spring for effecting frictional driving engagement between said surfaces. V r I 7. A power transmittin clutch mechanism comprising a rotatable driving member, a coaxial rotatable driven memberia centrifugally responsive pawl carried by one of said members, an annular portion on said other member having an opening therein for receiving said pawl at prede-v termind speed of said one member and substantially synchronous rotation of said members whereby to positivelyconnect said members in drive, and means for blocking'engagement of said .pawl during asynchronous rotation of said mem e s o p i g n nte al. ing ar ie i nally of said annularportion and having a tapered surface engageable with a complementary tapered surface on saidother member, and having a recess in theplane of said pawl receiving opening for permittin passage therethrough of said pawl when effecting engagement in said opening and having a blocking portion at each endof said recess for blocking engagement of the pawl and a spring for biasing said? tapered surfaces into engagement for effecting a frictional drive connection between said ring and other member.

8 A power transmitting clutch mechanism determined speed of said one member and sub stantially synchronous rotation of said members whereby to positively connect said members in drive, and meansfor blocking engagement of said pawl during asynchronous rotation of said members comprising an integ-ral'ring carried'inter-. nally of said annular portion and having a ta pered surface engageable with a complementary tapered surface on said other member, and hav ing a recess in the plane of said pawl receiving opening for permitting passage therethrough of said-pawl when effecting engagement in said opening and having a pawl blocking portion at each end of said recess,;a.springfor biasingv said tapered surfaces into engagement for effecting a frictional driveconnectionbetween said ring and other-member, and means on said ring and said one member providing a' positive limited lost motion connection between said ring and a positive drive connection between; said core and shell, anintegralipawl blockeriringi interposed radially between said core and shell,a circumferamazes 11 Av power transmitting clutch mechanism,

comprising a rotatable pawl carrying core, a radially movable centrifugally responsive pawl carried by said core, a rotatable shell having an opening therein for receiving said pawl to effect a positive drive connection between said core and shell, an integral pawl blocker ring having a circumferential blocker portion and a circumferential tapered surface in the same general circumferential plane as the blocker portion engageable with a complementary tapered surface on' said shell, spring means acting directly on said ring for biasing said surfaces into engagement for effecting a frictional drive connection between said ring and shell and means on said ring for limiting relative rotation between said ring and pawl.v g I 12. A power transmitting clutch mechanism comprising a rotatable pawl carrying core, a radially movable centrifugally responsive pawl carried by said core, a rotatable shell having an opening therein for receiving said pawl to effect a positive, drive connection between said core and shell, an integral pawl blocker ring having a circumferential blocker portion and a circumferentialtapered surface endwise of the blocker portion engageable with a complementary tapered surface on'said shell, spring means acting directly on said ringfor biasing said surfaces into engagement for effecting a frictional drive connec tion between said ring and shell and means providing a limited lost motionconnection between said ring and core. r

13. A power transmitting clutch mechanism comprising a, driving member, a coaxial driven member, a centrifugally responsive pawl carried by one of said members and interengageable with the .otherof said members at predetermined speed of said one member and synchronous rotation of said members for positively connecting said members in drive, a pawl blocker element intermediatesaid members transversely of the axis of saidmembers, said blocker element having a portion thereof in frictional drive connection with said'other member and having a cylindrical portionin a positive lost motion driving connection withsaidpawl, and said cylindrical portion having arecess therein for permitting passage therethrough of said pawl and having a portion at each circumferential end of said recess for positioning over the end of said pawl to block engagement thereof under asynchronous operation of said members. I I

' EDWIN R. MAURER.

. REFERENCES crrsn The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date 2,194,787 Dunn Mar. 26, 1940 2,273,623 OII" Apr, 7, 1942 2,448,539 Maurer i Sept. 7, 1948 

